1. Field of the Invention
The present invention relates to a device for conveying book blocks on a conveying line of a machine for producing books, magazines, or the like, along which conveying line a revolving conveying element is installed, which conveys the book blocks and is designed with finger-like pushers that are mounted on a traction mechanism and project into a conveying channel transversely to the conveying direction.
2. Description of the Related Art
Devices of the aforementioned type are known, for example, in installations for producing perfect-bound book blocks or books and in back-gluing machines, especially for thread-stitched book blocks.
In gathering machines, to form loose book blocks by feeders arranged along a conveying line, a conveying channel is loaded with printed products, and the book blocks, which are formed from stacked printed products are fed, standing on the spine of the book block, to a perfect binder. On the conveyance path, the loose book blocks are set up vertically, so that they can be inserted from below into the revolving conveyor clamps of a perfect binder. For this purpose, the gathering machine has pushers, which are mounted on a traction mechanism and project into a conveying channel and, during the formation of the loose book blocks, convey the latter by pushing against the so-called head or foot edge of the book block. During this process, the book block is turned about 90° in a vertical plane transverse to the direction of conveyance by a setting up element, so that it arrives at the perfect binder standing on its spine. In this conveyor section, the book block passes the setting up element, which is winding more or less helically in the conveying direction, where the book block is set on its spine, and the pusher is successively shifted into a horizontal position by a guide slot.
Both during the gathering of the printed products and during the transfer from the gathering machine to the perfect binder, it happens that printed products collide on the conveying tract and are displaced relative to the conveying direction, so that a backup then develops, which can cause the pusher, which is made of plastic, to break. Furthermore, in addition to the breaking of the pusher finger, the hinge, the holder, and/or chain links of the traction mechanism are damaged and thus must be replaced. This results in increased repair expense, especially since there are only “a few” places along the conveying line at which there is enough room to be able to repair the damage.
If the damage involves the chain, the tension on it must be released to replace the links. Accessibility to the chain with tools is limited in most cases, and it is no simple matter for the repairman to do his job properly in tight spaces with screws, nuts, bolts, and lock rings.